Portable electronic devices such as smartphones, personal digital assistances (PDAs), electronic book readers, or the like often use touch screens as image display sections and input sections. Such a portable device may use, as a main character input unit, a software keyboard, on screen keyboard (OSK), a screen keyboard, or the like displayed on a touch screen. A software keyboard may be used for enabling character input on a touch screen.
A user who has mastered typing remembers a relative layout of keys on a keyboard as physical feeling of fingers. A hardware keyboard includes buttons (keys) that correspond to character outputs and provide press feeling independently of one another. When a user touches these independent keys of the hardware keyboard during typing, the user can know where a finger being used for typing is placed (e.g., on a key or on a gap between keys) as a sense of touch of the finger.
With a software keyboard or the like, fingers cannot obtain any tactile information on the typing positions during typing. Thus, even a user who remembers a relative layout as a physical feeling cannot finely adjust the typing positions. Consequently, when such a user performs touch typing with a software keyboard or the like having a fixed layout, the typing position often shifts from a set key position, and even a user who has mastered touch typing tends to increase mistakes of typing unintended keys.